In U.S. Pat. No. 3,777,908 and co-pending U.S. application Ser. No. 568,853 , filed Apr. 17, 1975, there is disclosed an apparatus for plucking fibers from a plurality of bales arranged in two parallel rows behind each of a plurality of fiber feeding machines, as for example bale opener machines like those disclosed in U.s. Pat. No. 3,132,709 to Lytton, and delivering such plucked fibers to the fiber feeding machines. This apparatus generally includes a fiber plucker device that is automatically transported along and across the rows of bales on an elevated track system or the like, and an automatic control system is provided for determining the particular bales from which fiber is plucked.
More specially, each fiber feeding machine includes a photo-electric cell which produces a signal when the hopper of such fiber feeding machine is empty or requires more fibers, and the fiber plucker, in response to receiving such signal, is moved to a position adjacent the signaling machine whereupon it moves along one or the other of the rows of bales behind such machine and sequentially plucks fibers from each bale in the row and then transports the plucked fibers to the signaling maching where the fibers are released into hopper thereof. Two rows of longitudinally aligned bales are located behind each machine to permit replenishing of one row without interrupting or interferring with the plucking operation from the other row, and to permit a large number of bales (e.g. ten bales) to be placed directly behind a hopper having a limited width. The control system includes a selector switch which has three settings, namely "left," "right, " and "automatic."
AT the left setting, the fiber plucker device will only travel down the left bale row of any signaling machine to pluck fibers sequentially from the bales therein, while at the right setting the fiber plucker device will operate similarly along the right bale row of any signaling hopper. At the automatic setting, the fiber plucker device will first pluck fibers from the left bale row in response to a signal from a machine, and, upon return to such machine in response to a later signal, will pluck fibers from the right bale row, after which it will continue to alternate between such rows in response to subsequent signals.
It is to be noted that in this prior art machine, the fiber plucker stops at each bale in a bale row to remove fibers therefrom and then delivers such fibers to the corresponding machine, whereupon it returns to the next bale in such row and repeats the process sequentially for every bale in the row.
While this operational sequence works quite satisfactory in most fiber blending operations, particularly those where a desired fiber blend requires blending of fibers from a relatively large number of bales in a bale laydown, it has been found that this equipment has certain drawbacks where "short" blends are desired which require fibers from only a small number of bales (e.g. between 2 and 6) of different fiber content.
Thus, if the equipment is designed for five bale positions in each row of bales and only two different bales are necessary for a particular blend, it was necessary to remove the other bales from three of the bale positions in a row, and while this adjustment resulted in the proper fibers being taken to the hopper for blending, it resulted in a significant waste of time because the fiber plucker nevertheless traveled to the empty bale positions and went through the motions of plucking fibers from non-existent bales. Since the empty bale positions would almost always be the bale positions farthest from the hopper, the time waste became even more acute.
This time waste, in addition to the obvious result of limiting the number of hoppers which one fiber plucker could reasonably service, also resulted in some cases in inconsistent blends of inferior quality because of the time lag caused by the fiber plucker going to a number of empty bale positions. Such inferior blends are even more frequent where the plurality of of fiber feeding machines are arranged to form stacked layers of fibers onto a common conveyor belt because a time lag in getting the proper quantity of plucked fibers to a particular fiber feeding machine could result in an inadequate layer of fibers being deposited on the common conveyor belt.
In accordance with the present invention, the control system for the fiber feeding and transporting equipment has been improved to render such equipment more versatile, and to improve the manner in which such equipment deals with the drawbacks of the prior art equipment as discussed above.